var myAlert = new myAlert();

var websocket = null;

//判断当前浏览器是否支持WebSocket
if('WebSocket' in window){
    websocket = new WebSocket("ws://localhost/socket/"+document.getElementById('username').innerText);
}else{
    alert('Not support websocket')
}

//连接发生错误的回调方法
websocket.onerror = function(){
    //setMessageInnerHTML("error");
};

//连接成功建立的回调方法
websocket.onopen = function(event){
    //setMessageInnerHTML("open");
}

//接收到消息的回调方法
websocket.onmessage = function(event){
    setMessageInnerHTML(event.data);
}

//连接关闭的回调方法
websocket.onclose = function(){
    //setMessageInnerHTML("close");
}

//监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
window.onbeforeunload = function(){
    websocket.close();
}

//将消息显示在网页上
function setMessageInnerHTML(innerHTML){
    if(innerHTML == "update")
        location.reload();
    else {
        //alert(innerHTML);
        myAlert.alert('任务',innerHTML);
        document.getElementById('task').innerHTML = "任务：" + innerHTML + '<br/>';
    }
}

//关闭连接
function closeWebSocket(){
    websocket.close();
}

//发送消息
function send(){
    var task = document.getElementById('task').value;
    websocket.send(task);
}
